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In recent years great advances in the field of biomedical engineering and organic electronics have been achieved. One promising application would be the regulation of blood glucose concentration in type 2 diabetes patients. This application would eliminate medication and would improve the standard of life. To achieve this goal a system is needed which receives information about the glucose concentration and reacts upon it. This output reaction could then be used to stimulate the body's own glucose regulation mechanisms. This thesis combined a glucose sensor with an artificial neuron to take the first step towards such a system. Two different artificial neurons, the Axon-Hillock neuron and the astable multivibrator, were characterized and examined upon their usability. The Axon-Hillock, build with organic electrochemical transistors, revealed that it could be applied for both regulating high and low blood glucose concentrations. The astable multivibrator, build with silicon-based transistors, was not as functional as the Axon-Hillock neuron but with more development it could become as good. The placement of the glucose sensor in the astable multivibrator circuit is essential parameter to consider. The results demonstrate that the examined system is functional and could become a part of a larger closed-loop system. Future tests on an animal model may demonstrate its viability as a treatment for type 2 diabetes.

In recent years great advances in the field of biomedical engineering and organic electronics have been achieved. One promising application would be the regulation of blood glucose concentration in type 2 diabetes patients. This application would eliminate medication and would improve the standard of life. To achieve this goal a system is needed which receives information about the glucose concentration and reacts upon it. This output reaction could then be used to stimulate the body's own glucose regulation mechanisms. This thesis combined a glucose sensor with an artificial neuron to take the first step towards such a system. Two different artificial neurons, the Axon-Hillock neuron and the astable multivibrator, were characterized and examined upon their usability. The Axon-Hillock, build with organic electrochemical transistors, revealed that it could be applied for both regulating high and low blood glucose concentrations. The astable multivibrator, build with silicon-based transistors, was not as functional as the Axon-Hillock neuron but with more development it could become as good. The placement of the glucose sensor in the astable multivibrator circuit is essential parameter to consider. The results demonstrate that the examined system is functional and could become a part of a larger closed-loop system. Future tests on an animal model may demonstrate its viability as a treatment for type 2 diabetes.

The 5,10,15-trihexyl-10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole core, namely triindole, is well-known for its prominent hole-transporting properties and air stability. The functionalization of this core is also rather versatile, which allows the modulation of its properties by anchoring targeted scaffolds to different positions, e.g. 3,8,13 (para with respect to the nitrogens), 2,7,12 (analogously meta) or the nitrogen heteroatoms. Therefore, triindole excels as a pivotal semiconductor to be exploited in long-lasting organic thin-film transistors (OTFTs). This report aims to shed light on the effect of functionalizing whether para or meta positions with sulfurated moieties, in the pursuit of an enhanced performance in OTFTs. Remarkably, meta-substituted derivatives outshone their para- counterparts in terms of thermal, optical, intermolecular arrangement and semiconductor properties, claiming mobility values up to 2 × 10-3 cm2 V-1 s-1 and a shelf lifetime beyond the analyzed period of 5 months. Analysis of the thin films by grazing incidence X-ray diffraction (GIRXD) and atomic force microscopy (AFM) revealed that the meta-substitution also induces a higher degree of order and better morphology, further corroborating the potential of this structural approach., Peer Reviewed, Postprint (published version)

Bioelectronics, a field that bridges biology and electronics, has a rich history dating back to the 18th century. The inception of bioelectronics is generally attributed to Luigi Galvani, who in the late 1700s discovered that frog legs twitch as if alive when struck by electrical current. Consequently, this was the idea leading to what is known as animal electricity, which is considered the precursor to modern bioelectronics. Furthermore, in the mid-1800s, the electrical phenomena of exposed cerebral hemispheres in rabbits and monkeys were discovered by Richard Caton leading to the advancement in the 20th century bringing us closer to what we refer as bioelectronics nowadays, with the development of medical devices to aid with cardiological or hearing disorders such as the pacemaker and cochlear implants. What is more, a big milestone in the field of bioelectronics was the invention of the transistor in the middle of the 20th century opening countless new possibilities for biocompatible devices and electronic miniaturization. Nowadays bioelectronics have been evolving into a broad and diverse field with applications ranging from medical imaging to even genetic modification. The focus is on areas like bioelectronic medicine, neural interfaces and biosensors as well as the development and testing of new biocompatible materials. The field is growing every day driven by advancements in both organic electronics and biology. As our understanding is expanding more about the properties of biological cells and tissues, the potential ideas and applications will also continue to grow. Currently, the state of the art is Neuralink with the aim of creating a brain-computer interface that could potentially restore autonomy to those with medical needs that could not be met with the current advancements in technology. A device containing a chip and several electrode arrays of more than 1,000 super thin, flexible conductors that a surgical robot carefully implants into the cerebra

Bioelectronics represents an interdisciplinary field merging biology with electronics with the focus on developing devices that interact with biological systems. Therefore, bioelectronics can help us to understand and utilize biological processes with electronic means. This can aid in the progression of healthcare such as improved diagnostic tools, innovative therapy, or personalized medicine. Interfacing biology and electronics presents significant challenges in material science, necessitating the continuous exploration of new materials and measurement systems that meet both electronic and biological requirements. Organic mixed ionic-electronic conductive polymers are one material class that has gained great interest due to, as the name suggests, their dual ionic and electronic properties. Furthermore, these polymers have shown greatly adaptability at interfacing with biology, often superior to traditional materials as has been observed in neural probes. This curious interplay of ions and electrons in these polymers is harnessed by organic electrochemical transistors (OECTs), which transduce biological signals into electrical ones. OECTs are used to amplify measured electric signals or when functionalized with specific biorecognition elements to detect analytes. Given the operation principle of OECTs within aqueous environments, a variety of (bio-)sensors can be realized to interact with biological processes based on capacitive or faradaic currents. An adaptable sensor platform that can be used as a point-of-care device is highly sought after, as for example glucose sensors. In general, biosensors and their point-of-care applications play an important role in society for diagnostics, as evidenced by the COVID-19 pandemic, and for personalized medicine. This work explores various aspects of OECT biosensors, including capacitive sensors with aptamers, enzymatic sensing, and enzymatically polymerized OECTs. OECTs are integrated with recognition elements on different s

Bioelectronics, a field that bridges biology and electronics, has a rich history dating back to the 18th century. The inception of bioelectronics is generally attributed to Luigi Galvani, who in the late 1700s discovered that frog legs twitch as if alive when struck by electrical current. Consequently, this was the idea leading to what is known as animal electricity, which is considered the precursor to modern bioelectronics. Furthermore, in the mid-1800s, the electrical phenomena of exposed cerebral hemispheres in rabbits and monkeys were discovered by Richard Caton leading to the advancement in the 20th century bringing us closer to what we refer as bioelectronics nowadays, with the development of medical devices to aid with cardiological or hearing disorders such as the pacemaker and cochlear implants. What is more, a big milestone in the field of bioelectronics was the invention of the transistor in the middle of the 20th century opening countless new possibilities for biocompatible devices and electronic miniaturization. Nowadays bioelectronics have been evolving into a broad and diverse field with applications ranging from medical imaging to even genetic modification. The focus is on areas like bioelectronic medicine, neural interfaces and biosensors as well as the development and testing of new biocompatible materials. The field is growing every day driven by advancements in both organic electronics and biology. As our understanding is expanding more about the properties of biological cells and tissues, the potential ideas and applications will also continue to grow. Currently, the state of the art is Neuralink with the aim of creating a brain-computer interface that could potentially restore autonomy to those with medical needs that could not be met with the current advancements in technology. A device containing a chip and several electrode arrays of more than 1,000 super thin, flexible conductors that a surgical robot carefully implants into the cerebra

Bioelectronics, a field that bridges biology and electronics, has a rich history dating back to the 18th century. The inception of bioelectronics is generally attributed to Luigi Galvani, who in the late 1700s discovered that frog legs twitch as if alive when struck by electrical current. Consequently, this was the idea leading to what is known as animal electricity, which is considered the precursor to modern bioelectronics. Furthermore, in the mid-1800s, the electrical phenomena of exposed cerebral hemispheres in rabbits and monkeys were discovered by Richard Caton leading to the advancement in the 20th century bringing us closer to what we refer as bioelectronics nowadays, with the development of medical devices to aid with cardiological or hearing disorders such as the pacemaker and cochlear implants. What is more, a big milestone in the field of bioelectronics was the invention of the transistor in the middle of the 20th century opening countless new possibilities for biocompatible devices and electronic miniaturization. Nowadays bioelectronics have been evolving into a broad and diverse field with applications ranging from medical imaging to even genetic modification. The focus is on areas like bioelectronic medicine, neural interfaces and biosensors as well as the development and testing of new biocompatible materials. The field is growing every day driven by advancements in both organic electronics and biology. As our understanding is expanding more about the properties of biological cells and tissues, the potential ideas and applications will also continue to grow. Currently, the state of the art is Neuralink with the aim of creating a brain-computer interface that could potentially restore autonomy to those with medical needs that could not be met with the current advancements in technology. A device containing a chip and several electrode arrays of more than 1,000 super thin, flexible conductors that a surgical robot carefully implants into the cerebra

Ionically and electronically conducting polymers are celebrated for their distinct electronic characteristics, flexibility, and processability, making them vital in diverse fields such as ion exchange membranes, energy devices, and biomedical technologies. This dissertation delves into polymeric charge conduction materials, distinguishing them based on the type of charge carriers involved: ions, electronic charge carriers (polarons), or a combination of both. The study differentiates between electronic doping, which introduces polaronic and ionic charges, and purely ionic doping, achieved by adding small-molecule salts to introduce ionic charges. The first section of the study explores the structure-property relationships, illustrating how disordered polymer domains are linked to ionic charge carrier conduction and ordered domains to electronic conductivity. This section emphasizes the significance of the coexistence of these different phases within a single material, which facilitates mixed conduction.A focal point of the research is the investigation of doping processes in polymers. The dissertation's second chapter examines the nuances of electronic doping, particularly the mechanisms of Brønsted acid-induced oxidation in conjugated polymer thin films. This investigation reveals that such doping leads to self-limiting diffusion, resulting in stable dopant concentration gradients, optimal for creating heterojunctions. Subsequently, the dissertation pivots to polyelectrolyte design, examining the interactions between ionic charge carriers (Li+) and photoresponsive azo moieties attached to a polymer backbone. A notable discovery here is that semicrystalline polymers can achieve up to sevenfold higher conductivity than their amorphous counterparts due to Li+ complexation, challenging the conventional wisdom that favors disorder for enhanced ionic conductivity. The final major contribution of this work is the development of resonant scattering techniques for simultane

Organic semiconductors are a family of pi-conjugated compounds used in many applications, such as displays, bioelectronics, and thermoelectrics. However, their susceptibility to processing-induced contamination is not well understood. Here, it is shown that many organic electronic devices reported so far may have been unintentionally contaminated, thus affecting their performance, water uptake, and thin film properties. Nuclear magnetic resonance spectroscopy is used to detect and quantify contaminants originating from the glovebox atmosphere and common laboratory consumables used during device fabrication. Importantly, this in-depth understanding of the sources of contamination allows the establishment of clean fabrication protocols, and the fabrication of organic field effect transistors (OFETs) with improved performance and stability. This study highlights the role of unintentional contaminants in organic electronic devices, and demonstrates that certain stringent processing conditions need to be met to avoid scientific misinterpretation, ensure device reproducibility, and facilitate performance stability. The experimental procedures and conditions used herein are typical of those used by many groups in the field of solution-processed organic semiconductors. Therefore, the insights gained into the effects of contamination are likely to be broadly applicable to studies, not just of OFETs, but also of other devices based on these materials., QC 20240626

Organic semiconductors have been widely applied to electronic devices including organic solar cells (OSCs), and organic photodetectors (OPDs) in the last decades for their lightweight, flexibility, and great industry potential for high throughput solution processing and roll-to-roll printing technologies. However, traditional solvents used for these organic photovoltaics processing conditions are commonly highly toxic halogenated organic solvents like chlorobenzene (CB), o-dichlorobenzene (o-DCB), and chloroform (CF) which are not only harmful to human health upon exposure but can also cause long-term effects on the ecosystem. Consequently, research on halogen-free/ “green solvents” (such as xylene, 2-methyltetrahydrofuran (2-MeTHF), methanol, water, etc.) processable organic semiconductors are essential to moving organic photovoltaics from bench chemistry towards real-life applications. In this thesis, three studies are carried out to enhance the sensing performance, as well as to better understand the device physics of bulk heterojunction (BHJ) OPVs and OPDs. The design, fabrication, optimization, as well as characterization of green-solvent processing organic semiconductors, have been discussed in detail including OPV and OPD systems. The characterization of the solid-state properties of the optimized active layers in these organic electronic devices is further included. The bulk-heterojunction (BHJ) thin films processed from green solvents were characterized with different techniques at different length scales, including atomic force microscopy (AFM), transmission electron microscopy (TEM), grazing-incidence wide-angle X-ray scattering (GIWAXS) and solid-state nuclear magnetic resonance (ssNMR) spectroscopy. The first study gains insights into the structure–processing–property correlation of a PPDT2FBT: PC61BM bulk-heterojunction (BHJ) system processed from a green solvent, ortho-xylene (o-XY). This system is investigated in comparison with the same blend proces

In today’s digital era, electronics are integral to most activities in our daily lives, offering swift and global communication, powerful data processing tools, and advanced sensor devices. However, there are drawbacks to the exponentially growing demand for electronics, such as the depletion of fossil resources, and the complexities surrounding recycling electronic waste (E-waste). As we gradually step into the era of sustainability, it is necessary to explore alternative resources and develop greener electronic technologies. For this purpose, organic electronics (OE) has emerged as an interesting alternative, owning to its potential for low-energy fabrication and use of organic materials composed of Earth-abundant elements. The term "organic electronics" has been used widely to refer to electrical devices crafted from organic materials, typically semiconducting polymers (sCPs). This arises from the fact that most developed OE devices such as solar cells, transistors, supercapacitors, and batteries are centered around such materials. Along with the development of different semiconducting polymer varieties, materials from various natural resources have also been explored for devices’ electrodes, binders, and electrolytes. Among them, materials from the forest have emerged as abundant, renewable, and valuable options. For many years, wood has been tailored and utilized as a device template, while its components including cellulose fibrils and lignin have been widely used as structural or active components in OE. Lignin has now become an important electrode and electrolyte active material in energy storage devices. This thesis presents new approaches and findings in the utilization of wood and lignin as active components in different OE applications. The thesis centers around two primary themes, in which the first involves the development and utilization of conductive wood (CW), containing lignin, and lignin nanoparticles (LNPs) for supercapacitors and battery applica

Organic semiconductors are a family of pi-conjugated compounds used in many applications, such as displays, bioelectronics, and thermoelectrics. However, their susceptibility to processing-induced contamination is not well understood. Here, it is shown that many organic electronic devices reported so far may have been unintentionally contaminated, thus affecting their performance, water uptake, and thin film properties. Nuclear magnetic resonance spectroscopy is used to detect and quantify contaminants originating from the glovebox atmosphere and common laboratory consumables used during device fabrication. Importantly, this in-depth understanding of the sources of contamination allows the establishment of clean fabrication protocols, and the fabrication of organic field effect transistors (OFETs) with improved performance and stability. This study highlights the role of unintentional contaminants in organic electronic devices, and demonstrates that certain stringent processing conditions need to be met to avoid scientific misinterpretation, ensure device reproducibility, and facilitate performance stability. The experimental procedures and conditions used herein are typical of those used by many groups in the field of solution-processed organic semiconductors. Therefore, the insights gained into the effects of contamination are likely to be broadly applicable to studies, not just of OFETs, but also of other devices based on these materials., SCOPUS: ar.j, info:eu-repo/semantics/published

In today’s digital era, electronics are integral to most activities in our daily lives, offering swift and global communication, powerful data processing tools, and advanced sensor devices. However, there are drawbacks to the exponentially growing demand for electronics, such as the depletion of fossil resources, and the complexities surrounding recycling electronic waste (E-waste). As we gradually step into the era of sustainability, it is necessary to explore alternative resources and develop greener electronic technologies. For this purpose, organic electronics (OE) has emerged as an interesting alternative, owning to its potential for low-energy fabrication and use of organic materials composed of Earth-abundant elements. The term "organic electronics" has been used widely to refer to electrical devices crafted from organic materials, typically semiconducting polymers (sCPs). This arises from the fact that most developed OE devices such as solar cells, transistors, supercapacitors, and batteries are centered around such materials. Along with the development of different semiconducting polymer varieties, materials from various natural resources have also been explored for devices’ electrodes, binders, and electrolytes. Among them, materials from the forest have emerged as abundant, renewable, and valuable options. For many years, wood has been tailored and utilized as a device template, while its components including cellulose fibrils and lignin have been widely used as structural or active components in OE. Lignin has now become an important electrode and electrolyte active material in energy storage devices. This thesis presents new approaches and findings in the utilization of wood and lignin as active components in different OE applications. The thesis centers around two primary themes, in which the first involves the development and utilization of conductive wood (CW), containing lignin, and lignin nanoparticles (LNPs) for supercapacitors and battery applica

In today’s digital era, electronics are integral to most activities in our daily lives, offering swift and global communication, powerful data processing tools, and advanced sensor devices. However, there are drawbacks to the exponentially growing demand for electronics, such as the depletion of fossil resources, and the complexities surrounding recycling electronic waste (E-waste). As we gradually step into the era of sustainability, it is necessary to explore alternative resources and develop greener electronic technologies. For this purpose, organic electronics (OE) has emerged as an interesting alternative, owning to its potential for low-energy fabrication and use of organic materials composed of Earth-abundant elements. The term "organic electronics" has been used widely to refer to electrical devices crafted from organic materials, typically semiconducting polymers (sCPs). This arises from the fact that most developed OE devices such as solar cells, transistors, supercapacitors, and batteries are centered around such materials. Along with the development of different semiconducting polymer varieties, materials from various natural resources have also been explored for devices’ electrodes, binders, and electrolytes. Among them, materials from the forest have emerged as abundant, renewable, and valuable options. For many years, wood has been tailored and utilized as a device template, while its components including cellulose fibrils and lignin have been widely used as structural or active components in OE. Lignin has now become an important electrode and electrolyte active material in energy storage devices. This thesis presents new approaches and findings in the utilization of wood and lignin as active components in different OE applications. The thesis centers around two primary themes, in which the first involves the development and utilization of conductive wood (CW), containing lignin, and lignin nanoparticles (LNPs) for supercapacitors and battery applica

In today’s digital era, electronics are integral to most activities in our daily lives, offering swift and global communication, powerful data processing tools, and advanced sensor devices. However, there are drawbacks to the exponentially growing demand for electronics, such as the depletion of fossil resources, and the complexities surrounding recycling electronic waste (E-waste). As we gradually step into the era of sustainability, it is necessary to explore alternative resources and develop greener electronic technologies. For this purpose, organic electronics (OE) has emerged as an interesting alternative, owning to its potential for low-energy fabrication and use of organic materials composed of Earth-abundant elements. The term "organic electronics" has been used widely to refer to electrical devices crafted from organic materials, typically semiconducting polymers (sCPs). This arises from the fact that most developed OE devices such as solar cells, transistors, supercapacitors, and batteries are centered around such materials. Along with the development of different semiconducting polymer varieties, materials from various natural resources have also been explored for devices’ electrodes, binders, and electrolytes. Among them, materials from the forest have emerged as abundant, renewable, and valuable options. For many years, wood has been tailored and utilized as a device template, while its components including cellulose fibrils and lignin have been widely used as structural or active components in OE. Lignin has now become an important electrode and electrolyte active material in energy storage devices. This thesis presents new approaches and findings in the utilization of wood and lignin as active components in different OE applications. The thesis centers around two primary themes, in which the first involves the development and utilization of conductive wood (CW), containing lignin, and lignin nanoparticles (LNPs) for supercapacitors and battery applica

Printed electronics has enabled fabrication of electronic components and devices with low cost and more manufacturing and design freedom. This manufacturing technique has been successfully employed as a complementary fabrication approach to conventional nanolithography and microfabrication processes to create flexible and stretchable electronics. Fluoropolymers are crucial components in electronic devices and components, owing to their piezoelectric, triboelectric, pyroelectric, ferroelectric, and dielectric properties. In this research, we report fabrication of an inkjet-printed piezoelectric sensor based on poly (vinylidenefluoride trifluoroethylene) (PVDF-TrFE) and amine functionalized graphene oxide (AGO) for biomedical monitoring. The piezoelectric inkjet ink was obtained by optimizing the fluid mechanic properties based on Reynold and Weber numbers. The inkjet-printed freestanding film was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), wide-angle X-Ray scattering (WAXS), and differential scanning calorimetry (DSC). The piezoelectric sensor was fabricated by deposition of silver electrodes on each side of the piezoelectric film, followed by wiring and encapsulation. The sensor was subjected to an electric field of 1500 kV/cm to align the internal dipoles and induce net polarization. The fabricated flexible piezoelectric sensor was employed for monitoring biomedical signals such as finger tapping, joint bending, and swallowing. The sensor demonstrated outstanding sensitivity of 0.1 V/kPa and excellent repeatability and stability over 1000 cycles.

Encouraged by the outstanding performance of pentacene, the perspective over enhanced organic semiconductors has been focused on studying analogous ladder-type materials. In this context, the case of the diindolo[3,2-b:2',3'-h]carbazole core is a promising example of a semiconductor with improved stability. Herein, we report the synthesis of five diindolo[3,2-b:2',3'-h]carbazole derivatives displaying different alkylation patterning, as well as their integration in organic thin-film transistors. The elucidation of the single-crystal structures of three of the derivatives, accomplished by means of powder X-ray diffraction (PXRD), provided further insight into the intermolecular disposition of this core. As a result, the relationship between the structural design and the performance of the final devices could be analyzed. Globally, a scope of mobility values from 10–6 to 10–3 cm2 V–1 s–1 was achieved by just fine-tuning the length of the alkyl chains and the type of passivation layer applied onto the SiO2 surface. Remarkably, all the fabricated devices excel in terms of temporal and air stability with a shelf lifetime up to years, a coveted feature in organic electronics that confirms the potential of this core., ThisresearchwasfundedbytheMinisteriodeEconomía,IndústriayCompetitividad(grantnumberFUNMAT-PGC2018-095477-B-I00)., Peer Reviewed, Postprint (published version)

A grand challenge in materials science is to identify the impact of molecular composition and structure across a range of length scales on macroscopic properties. We demonstrate a unified experimental-theoretical framework that coordinates experimental measurements of mesoscale structure with molecular-level physical modeling to bridge multiple scales of physical behavior. Here we apply this framework to understand charge transport in a semiconducting polymer. Spatially-resolved nanodiffraction in a transmission electron microscope is combined with a self-consistent framework of the polymer chain statistics to yield a detailed picture of the polymer microstructure ranging from the molecular to device relevant scale. Using these data as inputs for charge transport calculations, the combined multiscale approach highlights the underrepresented role of defects in existing transport models. Short-range transport is shown to be more chaotic than is often pictured, with the drift velocity accounting for a small portion of overall charge motion. Local transport is sensitive to the alignment and geometry of polymer chains. At longer length scales, large domains and gradual grain boundaries funnel charges preferentially to certain regions, creating inhomogeneous charge distributions. While alignment generally improves mobility, these funneling effects negatively impact mobility. The microstructure is modified in silico to explore possible design rules, showing chain stiffness and alignment to be beneficial while local homogeneity has no positive effect. This combined approach creates a flexible and extensible pipeline for analyzing multiscale functional properties and a general strategy for extending the accesible length scales of experimental and theoretical probes by harnessing their combined strengths.

Printed and organic electronics have been intensely researched in the past few years, and their potential low-cost and sustainability benefits combined with their unique form properties makes them interesting from a product design perspective. However, there has been a lack of product design with printed and organic electronics, which has created a gap between research and market. The aim of this thesis is to find an application of printed and organic electronics in a previously unexplored application area. The thesis includes interviews and workshops with relevant actors, a SWOT analysis, and idea generation through brainstorming. It is found that printed and organic traceability tags (RFID/NFC) have the potential to facilitate circular business models in the fashion industry if they are developed to fulfil the identified requirements. Three concepts of how traceability tags can facilitate rental fashion are developed. The main identified potential benefits for the rental companies are reduced logistics costs and the possibility of data collection. The potentially low cost of printed and organic traceability tags would also enable rental companies with smaller profit margins to implement a digital traceability solution which would help the survival of these companies and accelerate the shift towards circular fashion. These findings contribute with a new possible application of printed and organic electronics. In order to reach the identified benefits, more research on printed and organic traceability tags is needed, as well as a full product development process of the three concepts. To really know whether this and other identified applications of POE could be viable on the market there is a need for economic and performance analysis to determine whether their applications can be successful. Further the authors also see a need for life cycle analyses on all types of POE applications to determine their environmental impact.

In sustainable development, one of the key factors is the usage of non-toxic and biodegradable natural substances for the development of green energy and technology. Photovoltaics and photoelectrochemical cells are the most promising candidates for renewable solar energy harvesting. Currently, photovoltaics and electronic device technologies are dominated by inorganic semiconductors. Thus, there is a continuous pursuit for alternative eco-friendly semiconductors both for electronics industry and renewable energy technologies. Carotenoids are naturally found coloured pigments which are of semiconducting nature. In nature, they form an integral part of light-harvesting photosystems in photosynthetic organisms, and are also present in several non-photosynthetic organisms playing other functional roles. The structural diversity of carotenoids and their molecular nature make them ideal candidates for devices requiring photo-sensitization, and controlled electrical conduction. Here, we review the potential application of carotenoids, with their advantages, limitations and prospects for further improvement in solar cell technology, photoelectrochemical cells, semiconductor surface modification, and organic electronics in general. We emphasize on the carotenoid based renewable energy production by using carotenoid based dye-sensitized solar cells and water-splitting photoelectrochemical cells. Thereafter, we summarize some of the studies with carotenoid based nanowire, light-emitting diodes, transistors and light sensors. Though, the application of carotenoids in renewable and sustainable technologies are still in nascent stage, prospects are high for carotenoid based solar harvesting and electronic devices that are cheaper, eco-friendly, biodegradable and biocompatible.

Flexible electronic systems such as wearable devices, sensors and electronic skin require power sources and sensing units that are mechanically robust, operational at low bending radius, and environmentally friendly. Recently, there has been an enormous interest in active materials such as thin film semiconductors, conductive polymers, and ion-electron conductors. These materials can be deposited with both printing and microfabrication techniques onto the flexible substrates such as plastics and paper. In addition, paper-based composites with nanofibrillated cellulose are favorable due to their mechanical strength, porosity, and solution-processability. Printing of such systems enables mass-production of large area electrochemical devices i.e., batteries, supercapacitors and fuel cells. Moreover, designing ultrathin devices for such concepts are promising for implantable and skin-like conformable electronics. The aim of this thesis is the development of flexible electronic devices where, both organic and inorganic materials are explored, and examples of smart packaging and wearable electronics are demonstrated. Within the thesis, two different fabrication approaches are presented to achieve flexible electronics: (1) fabrication of porous paper electrodes for printable, wearable supercapacitor applications, where our efforts towards sustainable solutions for energy storage and (2) development of ultraflexible devices for electronic skin and implantable electronics to attain miniaturized, ultrathin device concepts. Overall, high performance electronic devices and demonstrators shown here have a significant impact on portable hybrid systems and flexible electronics applications., Flexibla elektroniska system såsom kroppsburna enheter, sensorer och elektronisk hud kräver strömkällor och sensorenheter som är mekaniskt robusta, fungerar i böjt tillstånd och är miljövänliga. På senare tid har detta lett till ett enormt intresse för aktiva material som tunnfilmshalvledare, ledande polymerer och kombinerade jon- och elektronledare. Dessa material kan deponeras med både tryck- och mikrotillverkningstekniker på flexibla substrat som plast och papper. Vidare är pappersbaserade kompositer med nanofibrillerad cellulosa intressanta på grund av deras mekaniska styrka, porositet och möjlighet att processa i lösning. Tryckning av sådana system möjliggör massproduktion av elektrokemiska enheter med stor yta, dvs batterier, superkondensatorer och bränsleceller. För att ge hudliknande formbarhet och biokompatibilitet för implanterbara enheter är ultratunna enheter ett lovande koncept. Syftet med denna avhandling är att utveckla flexibla elektroniska enheter där både organiska och oorganiska material utforskas, och att demonstrera exempel på smarta förpackningar och kroppsburen elektronik. I avhandlingen presenteras två olika tillverkningsmetoder för flexibel elektronik: (1) tillverkning av porösa papperselektroder för tryckbara, kroppsburna superkondensatorer, syftande till hållbara lösningar för energilagring och (2) utveckling av ultraflexibla enheter för elektronisk hud och implanterbar elektronik för att uppnå miniatyriserade, ultratunna enhetskoncept. Sammantaget kan de högpresterande elektroniska enheter och demonstratorer som visas här ha stor betydelse för utvecklingen av bärbara hybridsystem och flexibel elektronik.

In sustainable development, one of the key factors is the usage of non-toxic and biodegradable natural substances for the development of green energy and technology. Photovoltaics and photoelectrochemical cells are the most promising candidates for renewable solar energy harvesting. Currently, photovoltaics and electronic device technologies are dominated by inorganic semiconductors. Thus, there is a continuous pursuit for alternative eco-friendly semiconductors both for electronics industry and renewable energy technologies. Carotenoids are naturally found coloured pigments which are of semiconducting nature. In nature, they form an integral part of light-harvesting photosystems in photosynthetic organisms, and are also present in several non-photosynthetic organisms playing other functional roles. The structural diversity of carotenoids and their molecular nature make them ideal candidates for devices requiring photo-sensitization, and controlled electrical conduction. Here, we review the potential application of carotenoids, with their advantages, limitations and prospects for further improvement in solar cell technology, photoelectrochemical cells, semiconductor surface modification, and organic electronics in general. We emphasize on the carotenoid based renewable energy production by using carotenoid based dye-sensitized solar cells and water-splitting photoelectrochemical cells. Thereafter, we summarize some of the studies with carotenoid based nanowire, light-emitting diodes, transistors and light sensors. Though, the application of carotenoids in renewable and sustainable technologies are still in nascent stage, prospects are high for carotenoid based solar harvesting and electronic devices that are cheaper, eco-friendly, biodegradable and biocompatible.

Printed and organic electronics have been intensely researched in the past few years, and their potential low-cost and sustainability benefits combined with their unique form properties makes them interesting from a product design perspective. However, there has been a lack of product design with printed and organic electronics, which has created a gap between research and market. The aim of this thesis is to find an application of printed and organic electronics in a previously unexplored application area. The thesis includes interviews and workshops with relevant actors, a SWOT analysis, and idea generation through brainstorming. It is found that printed and organic traceability tags (RFID/NFC) have the potential to facilitate circular business models in the fashion industry if they are developed to fulfil the identified requirements. Three concepts of how traceability tags can facilitate rental fashion are developed. The main identified potential benefits for the rental companies are reduced logistics costs and the possibility of data collection. The potentially low cost of printed and organic traceability tags would also enable rental companies with smaller profit margins to implement a digital traceability solution which would help the survival of these companies and accelerate the shift towards circular fashion. These findings contribute with a new possible application of printed and organic electronics. In order to reach the identified benefits, more research on printed and organic traceability tags is needed, as well as a full product development process of the three concepts. To really know whether this and other identified applications of POE could be viable on the market there is a need for economic and performance analysis to determine whether their applications can be successful. Further the authors also see a need for life cycle analyses on all types of POE applications to determine their environmental impact.

These recommendations are specifically for polymers and polymer systems showing a significant response to an electromagnetic field or one of its components (electric field or magnetic field), i.e., for electromagnetic-field-responsive polymer materials. The structures, processes, phenomena and quantities relating to this interdisciplinary field of materials science and technology are herein defined. Definitions are unambiguously explained and harmonized for wide acceptance by the chemistry, physics, polymer and materials science communities. A survey of typical electromagnetic-field-responsive polymers is included., source:https://www.degruyter.com/document/doi/10.1515/pac-2020-0501/html

Organic semiconducting polymers have attractive electronic, optical, and mechanical properties that make them materials of choice for large area flexible electronic devices. In these devices, the electronically active polymer components are micrometers in size, and sport negligible performance degradation upon bending the centimeter-scale flexible substrate onto which they are integrated. A closer look at the mechanical properties of the polymers, on the grain-scale and smaller, is not necessary in large area electronic applications. In emerging micromechanical and electromechanical applications where the organic polymer elements are flexed on length scales spanning their own micron-sized active areas, it becomes important to characterize the uniformity of their mechanical properties on the nanoscale. In this work, the authors use two precision nanomechanical characterization techniques, namely, atomic force microscope based PeakForce quantitative nanomechanical mapping (PF-QNM) and nanoindentation-based dynamical mechanical analysis (nano-DMA), to compare the modulus and the viscoelastic properties of organic polymers used routinely in organic electronics. They quantitatively demonstrate that the semiconducting near-amorphous organic polymer indacenodithiophene-co-benzothiadiazole (C16-IDTBT) has a higher carrier mobility, lower modulus, and greater nanoscale modulus areal uniformity compared to the semiconducting semicrystalline organic polymer poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (C14-PBTTT). Modulus homogeneity appears intrinsic to C16-IDTBT but can be improved in C14-PBTTT upon chemical doping., QC 20220607

The conductive polyelectrolyte complex poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is ubiquitous in research dealing with organic electronic devices (e.g., solar cells, wearable and implantable sensors, and electrochemical transistors). In many bioelectronic applications, the applicability of commercially available formulations of PEDOT:PSS (e.g., Clevios) is limited by its poor mechanical properties. Additives can be used to increase the compliance but pose a risk of leaching, which can result in device failure and increased toxicity (in biological settings). Thus, to increase the mechanical compliance of PEDOT:PSS without additives, we synthesized a library of intrinsically stretchable block copolymers. In particular, controlled radical polymerization using a reversible addition-fragmentation transfer process was used to generate block copolymers consisting of a block of PSS (of fixed length) appended to varying blocks of poly(poly(ethylene glycol) methyl ether acrylate) (PPEGMEA). These block copolymers (PSS(1)-b-PPEGMEA(x), where x ranges from 1 to 6) were used as scaffolds for oxidative polymerization of PEDOT. By increasing the lengths of the PPEGMEA segments on the PEDOT:[PSS(1)-b-PPEGMEA(1-6)] block copolymers, ("Block-1" to "Block-6"), or by blending these copolymers with PEDOT:PSS, the mechanical and electronic properties of the polymer can be tuned. Our results indicate that the polymer with the longest block of PPEGMEA, Block-6, had the highest fracture strain (75%) and lowest elastic modulus (9.7 MPa), though at the expense of conductivity (0.01 S cm-1). However, blending Block-6 with PEDOT:PSS to compensate for the insulating nature of the PPEGMEA resulted in increased conductivity [2.14 S cm-1 for Blend-6 (2:1)]. Finally, we showed that Block-6 outperforms a commercial formulation of PEDOT:PSS as a dry electrode for surface electromyography due to its favorable mechanical properties and better adhesion to skin.

Flexible electronic systems such as wearable devices, sensors and electronic skin require power sources and sensing units that are mechanically robust, operational at low bending radius, and environmentally friendly. Recently, there has been an enormous interest in active materials such as thin film semiconductors, conductive polymers, and ion-electron conductors. These materials can be deposited with both printing and microfabrication techniques onto the flexible substrates such as plastics and paper. In addition, paper-based composites with nanofibrillated cellulose are favorable due to their mechanical strength, porosity, and solution-processability. Printing of such systems enables mass-production of large area electrochemical devices i.e., batteries, supercapacitors and fuel cells. Moreover, designing ultrathin devices for such concepts are promising for implantable and skin-like conformable electronics. The aim of this thesis is the development of flexible electronic devices where, both organic and inorganic materials are explored, and examples of smart packaging and wearable electronics are demonstrated. Within the thesis, two different fabrication approaches are presented to achieve flexible electronics: (1) fabrication of porous paper electrodes for printable, wearable supercapacitor applications, where our efforts towards sustainable solutions for energy storage and (2) development of ultraflexible devices for electronic skin and implantable electronics to attain miniaturized, ultrathin device concepts. Overall, high performance electronic devices and demonstrators shown here have a significant impact on portable hybrid systems and flexible electronics applications., Flexibla elektroniska system såsom kroppsburna enheter, sensorer och elektronisk hud kräver strömkällor och sensorenheter som är mekaniskt robusta, fungerar i böjt tillstånd och är miljövänliga. På senare tid har detta lett till ett enormt intresse för aktiva material som tunnfilmshalvledare, ledande polymerer och kombinerade jon- och elektronledare. Dessa material kan deponeras med både tryck- och mikrotillverkningstekniker på flexibla substrat som plast och papper. Vidare är pappersbaserade kompositer med nanofibrillerad cellulosa intressanta på grund av deras mekaniska styrka, porositet och möjlighet att processa i lösning. Tryckning av sådana system möjliggör massproduktion av elektrokemiska enheter med stor yta, dvs batterier, superkondensatorer och bränsleceller. För att ge hudliknande formbarhet och biokompatibilitet för implanterbara enheter är ultratunna enheter ett lovande koncept. Syftet med denna avhandling är att utveckla flexibla elektroniska enheter där både organiska och oorganiska material utforskas, och att demonstrera exempel på smarta förpackningar och kroppsburen elektronik. I avhandlingen presenteras två olika tillverkningsmetoder för flexibel elektronik: (1) tillverkning av porösa papperselektroder för tryckbara, kroppsburna superkondensatorer, syftande till hållbara lösningar för energilagring och (2) utveckling av ultraflexibla enheter för elektronisk hud och implanterbar elektronik för att uppnå miniatyriserade, ultratunna enhetskoncept. Sammantaget kan de högpresterande elektroniska enheter och demonstratorer som visas här ha stor betydelse för utvecklingen av bärbara hybridsystem och flexibel elektronik.

R&D of OLEDs devices can benefit from the support of simulations. The highest level of insight can be obtained with 3D kinetic Monte Carlo. Concrete R&D case studies showing how 3D kinetic Monte Carlo simulations can be used to address OLED R&D challenges will be presented.

R&D of OLEDs devices can benefit from the support of simulations. The highest level of insight can be obtained with 3D kinetic Monte Carlo. Concrete R&D case studies showing how 3D kinetic Monte Carlo simulations can be used to address OLED R&D challenges will be presented.

Flexible electronic systems such as wearable devices, sensors and electronic skin require power sources and sensing units that are mechanically robust, operational at low bending radius, and environmentally friendly. Recently, there has been an enormous interest in active materials such as thin film semiconductors, conductive polymers, and ion-electron conductors. These materials can be deposited with both printing and microfabrication techniques onto the flexible substrates such as plastics and paper. In addition, paper-based composites with nanofibrillated cellulose are favorable due to their mechanical strength, porosity, and solution-processability. Printing of such systems enables mass-production of large area electrochemical devices i.e., batteries, supercapacitors and fuel cells. Moreover, designing ultrathin devices for such concepts are promising for implantable and skin-like conformable electronics. The aim of this thesis is the development of flexible electronic devices where, both organic and inorganic materials are explored, and examples of smart packaging and wearable electronics are demonstrated. Within the thesis, two different fabrication approaches are presented to achieve flexible electronics: (1) fabrication of porous paper electrodes for printable, wearable supercapacitor applications, where our efforts towards sustainable solutions for energy storage and (2) development of ultraflexible devices for electronic skin and implantable electronics to attain miniaturized, ultrathin device concepts. Overall, high performance electronic devices and demonstrators shown here have a significant impact on portable hybrid systems and flexible electronics applications., Flexibla elektroniska system såsom kroppsburna enheter, sensorer och elektronisk hud kräver strömkällor och sensorenheter som är mekaniskt robusta, fungerar i böjt tillstånd och är miljövänliga. På senare tid har detta lett till ett enormt intresse för aktiva material som tunnfilmshalvledare, ledande polymerer och kombinerade jon- och elektronledare. Dessa material kan deponeras med både tryck- och mikrotillverkningstekniker på flexibla substrat som plast och papper. Vidare är pappersbaserade kompositer med nanofibrillerad cellulosa intressanta på grund av deras mekaniska styrka, porositet och möjlighet att processa i lösning. Tryckning av sådana system möjliggör massproduktion av elektrokemiska enheter med stor yta, dvs batterier, superkondensatorer och bränsleceller. För att ge hudliknande formbarhet och biokompatibilitet för implanterbara enheter är ultratunna enheter ett lovande koncept. Syftet med denna avhandling är att utveckla flexibla elektroniska enheter där både organiska och oorganiska material utforskas, och att demonstrera exempel på smarta förpackningar och kroppsburen elektronik. I avhandlingen presenteras två olika tillverkningsmetoder för flexibel elektronik: (1) tillverkning av porösa papperselektroder för tryckbara, kroppsburna superkondensatorer, syftande till hållbara lösningar för energilagring och (2) utveckling av ultraflexibla enheter för elektronisk hud och implanterbar elektronik för att uppnå miniatyriserade, ultratunna enhetskoncept. Sammantaget kan de högpresterande elektroniska enheter och demonstratorer som visas här ha stor betydelse för utvecklingen av bärbara hybridsystem och flexibel elektronik.

Ultrastable glasses (mostly prepared from the vapor phase under optimized deposition conditions) represent a unique class of materials with low enthalpies and high kinetic stabilities. These highly stable and dense glasses show unique physicochemical properties, such as high thermal stability, improved mechanical properties or anomalous transitions into the supercooled liquid, offering unprecedented opportunities to understand many aspects of the glassy state. Their improved properties with respect to liquid-cooled glasses also open new prospects to their use in applications where liquid-cooled glasses failed or where not considered as usable materials. In this review article we summarize the state of the art of vapor-deposited (and other) ultrastable glasses with a focus on the mechanism of equilibration, the transformation to the liquid state and the low temperature properties. The review contains information on organic, metallic, polymeric and chalcogenide glasses and an updated list with relevant properties of all materials known today to form a stable glass.

Flexible electronic systems such as wearable devices, sensors and electronic skin require power sources and sensing units that are mechanically robust, operational at low bending radius, and environmentally friendly. Recently, there has been an enormous interest in active materials such as thin film semiconductors, conductive polymers, and ion-electron conductors. These materials can be deposited with both printing and microfabrication techniques onto the flexible substrates such as plastics and paper. In addition, paper-based composites with nanofibrillated cellulose are favorable due to their mechanical strength, porosity, and solution-processability. Printing of such systems enables mass-production of large area electrochemical devices i.e., batteries, supercapacitors and fuel cells. Moreover, designing ultrathin devices for such concepts are promising for implantable and skin-like conformable electronics. The aim of this thesis is the development of flexible electronic devices where, both organic and inorganic materials are explored, and examples of smart packaging and wearable electronics are demonstrated. Within the thesis, two different fabrication approaches are presented to achieve flexible electronics: (1) fabrication of porous paper electrodes for printable, wearable supercapacitor applications, where our efforts towards sustainable solutions for energy storage and (2) development of ultraflexible devices for electronic skin and implantable electronics to attain miniaturized, ultrathin device concepts. Overall, high performance electronic devices and demonstrators shown here have a significant impact on portable hybrid systems and flexible electronics applications., Flexibla elektroniska system såsom kroppsburna enheter, sensorer och elektronisk hud kräver strömkällor och sensorenheter som är mekaniskt robusta, fungerar i böjt tillstånd och är miljövänliga. På senare tid har detta lett till ett enormt intresse för aktiva material som tunnfilmshalvledare, ledande polymerer och kombinerade jon- och elektronledare. Dessa material kan deponeras med både tryck- och mikrotillverkningstekniker på flexibla substrat som plast och papper. Vidare är pappersbaserade kompositer med nanofibrillerad cellulosa intressanta på grund av deras mekaniska styrka, porositet och möjlighet att processa i lösning. Tryckning av sådana system möjliggör massproduktion av elektrokemiska enheter med stor yta, dvs batterier, superkondensatorer och bränsleceller. För att ge hudliknande formbarhet och biokompatibilitet för implanterbara enheter är ultratunna enheter ett lovande koncept. Syftet med denna avhandling är att utveckla flexibla elektroniska enheter där både organiska och oorganiska material utforskas, och att demonstrera exempel på smarta förpackningar och kroppsburen elektronik. I avhandlingen presenteras två olika tillverkningsmetoder för flexibel elektronik: (1) tillverkning av porösa papperselektroder för tryckbara, kroppsburna superkondensatorer, syftande till hållbara lösningar för energilagring och (2) utveckling av ultraflexibla enheter för elektronisk hud och implanterbar elektronik för att uppnå miniatyriserade, ultratunna enhetskoncept. Sammantaget kan de högpresterande elektroniska enheter och demonstratorer som visas här ha stor betydelse för utvecklingen av bärbara hybridsystem och flexibel elektronik.

Flexible electronic systems such as wearable devices, sensors and electronic skin require power sources and sensing units that are mechanically robust, operational at low bending radius, and environmentally friendly. Recently, there has been an enormous interest in active materials such as thin film semiconductors, conductive polymers, and ion-electron conductors. These materials can be deposited with both printing and microfabrication techniques onto the flexible substrates such as plastics and paper. In addition, paper-based composites with nanofibrillated cellulose are favorable due to their mechanical strength, porosity, and solution-processability. Printing of such systems enables mass-production of large area electrochemical devices i.e., batteries, supercapacitors and fuel cells. Moreover, designing ultrathin devices for such concepts are promising for implantable and skin-like conformable electronics. The aim of this thesis is the development of flexible electronic devices where, both organic and inorganic materials are explored, and examples of smart packaging and wearable electronics are demonstrated. Within the thesis, two different fabrication approaches are presented to achieve flexible electronics: (1) fabrication of porous paper electrodes for printable, wearable supercapacitor applications, where our efforts towards sustainable solutions for energy storage and (2) development of ultraflexible devices for electronic skin and implantable electronics to attain miniaturized, ultrathin device concepts. Overall, high performance electronic devices and demonstrators shown here have a significant impact on portable hybrid systems and flexible electronics applications., Flexibla elektroniska system såsom kroppsburna enheter, sensorer och elektronisk hud kräver strömkällor och sensorenheter som är mekaniskt robusta, fungerar i böjt tillstånd och är miljövänliga. På senare tid har detta lett till ett enormt intresse för aktiva material som tunnfilmshalvledare, ledande polymerer och kombinerade jon- och elektronledare. Dessa material kan deponeras med både tryck- och mikrotillverkningstekniker på flexibla substrat som plast och papper. Vidare är pappersbaserade kompositer med nanofibrillerad cellulosa intressanta på grund av deras mekaniska styrka, porositet och möjlighet att processa i lösning. Tryckning av sådana system möjliggör massproduktion av elektrokemiska enheter med stor yta, dvs batterier, superkondensatorer och bränsleceller. För att ge hudliknande formbarhet och biokompatibilitet för implanterbara enheter är ultratunna enheter ett lovande koncept. Syftet med denna avhandling är att utveckla flexibla elektroniska enheter där både organiska och oorganiska material utforskas, och att demonstrera exempel på smarta förpackningar och kroppsburen elektronik. I avhandlingen presenteras två olika tillverkningsmetoder för flexibel elektronik: (1) tillverkning av porösa papperselektroder för tryckbara, kroppsburna superkondensatorer, syftande till hållbara lösningar för energilagring och (2) utveckling av ultraflexibla enheter för elektronisk hud och implanterbar elektronik för att uppnå miniatyriserade, ultratunna enhetskoncept. Sammantaget kan de högpresterande elektroniska enheter och demonstratorer som visas här ha stor betydelse för utvecklingen av bärbara hybridsystem och flexibel elektronik.

Electrolyte-Gated Organic Field-Effect Transistors (EGOFETs) offer many opportunities for the development of low-cost and low-power electronics suitable for applications like sensors and point-of-care tests; however, EGOFETs can be affected by the drift of their operative point that causes signals distortion and loss of information during sensing applications. Here, a blend of 2,8-Difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) and polystyrene (PS) is used as the active material for the fabrication of dual-gate EGOFETs. We exploited the dual-gate architecture to improve EGOFETs stability by implementing digital feedback that uses the back-gate electrode to compensate dynamically for the transistor threshold voltage allowing us to fix its operative point for prolonged tests (>10 h) with different aqueous solutions (Milli-Q water, NaCl 0.1 M and a physiological solution). The presented real-time threshold voltage compensation does not only allow to steady EGOFETs DC output current, but it also preserves EGOFETs sensing capability for the detection of signals with frequencies as low as 1 Hz.

Organic semiconducting polymers have attractive electronic, optical, and mechanical properties that make them materials of choice for large area flexible electronic devices. In these devices, the electronically active polymer components are micrometers in size, and sport negligible performance degradation upon bending the centimeter-scale flexible substrate onto which they are integrated. A closer look at the mechanical properties of the polymers, on the grain-scale and smaller, is not necessary in large area electronic applications. In emerging micromechanical and electromechanical applications where the organic polymer elements are flexed on length scales spanning their own micron-sized active areas, it becomes important to characterize the uniformity of their mechanical properties on the nanoscale. In this work, the authors use two precision nanomechanical characterization techniques, namely, atomic force microscope based PeakForce quantitative nanomechanical mapping (PF-QNM) and nanoindentation-based dynamical mechanical analysis (nano-DMA), to compare the modulus and the viscoelastic properties of organic polymers used routinely in organic electronics. They quantitatively demonstrate that the semiconducting near-amorphous organic polymer indacenodithiophene-co-benzothiadiazole (C16-IDTBT) has a higher carrier mobility, lower modulus, and greater nanoscale modulus areal uniformity compared to the semiconducting semicrystalline organic polymer poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (C14-PBTTT). Modulus homogeneity appears intrinsic to C16-IDTBT but can be improved in C14-PBTTT upon chemical doping., SCOPUS: ar.j, info:eu-repo/semantics/published

Highly controlled drug delivery devices play an increasingly important role in the development of new neuroengineering tools. Stringent - and sometimes contradicting - demands are placed on such devices, ranging from robustness in freestanding devices, to overall device miniaturization, while maintaining precise spatiotemporal control of delivery with high chemical specificity and high on/off ratio. Here, design principles of a hybrid microfluidic iontronic probe that uses flow for long-range pressure-driven transport in combination with an iontronic tip that provides electronically fine-tuned pressure-free delivery are explored. Employing a computational model, the effects of decoupling the drug reservoir by exchanging a large passive reservoir with a smaller microfluidic system are reported. The transition at the microfluidic-iontronic interface is found to require an expanded ion exchange membrane inlet in combination with a constant fluidic flow, to allow a broad range of device operation, including low source concentrations and high delivery currents. Complementary to these findings, the free-standing hybrid probe monitored in real time by an external sensor is demonstrated. From these computational and experimental results, key design principles for iontronic devices are outlined that seek to use the efficient transport enabled by microfluidics, and further, key observations of hybrid microfluidic iontronic probes are explained., Additional Funding agencies: FLAG‐ERA. Grant Number: JTC2017; EPIGRAPH. Grant Number: ANR‐17‐GRF2‐0001; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linköping University. Grant Number: 2009‐00971; A*MIDEX ION. Grant Number: 2IONXXID/REID/ID17HRU208

Highly controlled drug delivery devices play an increasingly important role in the development of new neuroengineering tools. Stringent - and sometimes contradicting - demands are placed on such devices, ranging from robustness in freestanding devices, to overall device miniaturization, while maintaining precise spatiotemporal control of delivery with high chemical specificity and high on/off ratio. Here, design principles of a hybrid microfluidic iontronic probe that uses flow for long-range pressure-driven transport in combination with an iontronic tip that provides electronically fine-tuned pressure-free delivery are explored. Employing a computational model, the effects of decoupling the drug reservoir by exchanging a large passive reservoir with a smaller microfluidic system are reported. The transition at the microfluidic-iontronic interface is found to require an expanded ion exchange membrane inlet in combination with a constant fluidic flow, to allow a broad range of device operation, including low source concentrations and high delivery currents. Complementary to these findings, the free-standing hybrid probe monitored in real time by an external sensor is demonstrated. From these computational and experimental results, key design principles for iontronic devices are outlined that seek to use the efficient transport enabled by microfluidics, and further, key observations of hybrid microfluidic iontronic probes are explained., Additional Funding agencies: FLAG‐ERA. Grant Number: JTC2017; EPIGRAPH. Grant Number: ANR‐17‐GRF2‐0001; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linköping University. Grant Number: 2009‐00971; A*MIDEX ION. Grant Number: 2IONXXID/REID/ID17HRU208

The motto of University of California is “let there be light.” But how do we know whether there is light, especially the light that we cannot see with our eyes? The answer is photodetectors. Photodetection has long play an indispensable role in modern technologies. The research endeavors on organic photodetectors (OPDs) have been continuously increasing in the recent years since they promise great potential as a platform for photosensing, imaging, and optical communication. Compared to the established crystalline inorganic counterparts, OPDs show their unique attractiveness: tunable spectral activity, low-temperature and low-cost fabrication, light weight and mechanical flexibility, large-area solution/printing processibility, and versatile integration into complicated optoelectronics. In this thesis, three studies are carried out to enhance the sensing performance, as well as to better understand the device physics of bulk heterojunction (BHJ) OPDs. Notwithstanding the exciting progress made thus far for OPDs, efficient broadband detection, especially in the near infrared (NIR) region, still needs to be improved due to the challenges in simultaneously securing high photoresponse and low dark/noise current for narrow bandgap systems. For the first part, the focus is placed on achieving high NIR sensing performance for BHJ organic photodiodes. A novel ultranarrow bandgap (~1.2 eV) small molecule is used, which present the highest responsivity of 0.45-0.52 A/W in the spectral region of 920 – 940 nm. With well suppressed charge injection under reverse bias using thick junction approach, high NIR specific detectivity of ~1012 Jones can be obtained even at a large bias of 2 V. Subsequently, we touch an instability problem found for inverted structure OPDs, where a large inconsistency of dark current can be universally found between before- and after-illumination conditions, negatively impacting the crucial figures-of-merit such as specific detectivity. Systematic control

This dissertation is concerned with the fabrication and characterization of organic electrochemical transistors (OECTs) made from polyelectrolytes based on the material PCPDTBT-SO3-Na (CPE-Na). OECTs are electrolyte-gated transistors that allow the electrolyte to permeate into the bulk of the film and directly changes the doping state of the bulk of the semiconducting layer. The relationship between the molecular structure of the polyelectrolytes and the material properties are explored in the lens of optimizing device characteristics in OECTs. The first chapter of this thesis focuses on the development of OECTs made using PCPDTBT-SO3-K (CPE-K) as the active layer. While the large majority of OECT research still utilizes poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the active layer, a few new OECT materials have been recently reported. CPE-K has been used in the past for applications such as DNA-detection, thermoelectric devices and as interlayers in organic photovoltaic devices. Conjugated polyelectrolytes (CPEs) represent a promising and unique class of materials which are characterized by their conjugated carbon backbone and pendant ionic chains. Their water solubility in addition to their electronic and ionic conductivity makes them an ideal candidate for OECT applications. Using various spectroscopic and electric characterization techniques, CPE-K was fully characterized so that it could be accurately compared to other OECT materials reported in the literature. In fact, CPE-K is among the short list of high-performance OECT materials. The techniques used in this work was used to shed light on the operational mechanism of CPE-based OECTs. In addition, the effective use of interdigitated contacts was used to increase the transconductance of OECT devices.The second portion of this thesis expands on the work of CPE OECTs, by exploring their structure-property-relationship. A series of CPE-Na polymers with varying sidechain lengths were synt

Organic solar cells incorporating non-fullerene acceptors (NFAs) have reached remarkable power conversion efficiencies of over 18%. Unlike fullerene derivatives, NFAs tend to crystallize from solutions, resulting in bulk heterojunctions that include a crystalline acceptor phase. This must be considered in any morphology-function models. Here, it is confirmed that high-performing solution-processed indacenodithienothiophene-based NFAs, i.e., ITIC and its derivatives ITIC-M, ITIC-2F, and ITIC-Th, exhibit at least two crystalline forms. In addition to highly ordered polymorphs that form at high temperatures, NFAs arrange into a low-temperature metastable phase that is readily promoted via solution processing and leads to the highest device efficiencies. Intriguingly, the low-temperature forms seem to feature a continuous network that favors charge transport despite of a poorly order along the pi-pi stacking direction. As the optical absorption of the structurally more disordered low-temperature phase can surpass that of the more ordered polymorphs while displaying comparable-or even higher-charge transport properties, it is argued that such a packing structure is an important feature for reaching highest device efficiencies, thus, providing guidelines for future materials design and crystal engineering activities.

Multiferroic magnetoelectric composites are an attractive material system for multifunctional design due to their ability to bidirectionally couple magnetic and electric fields at nearly all length and time scales. Unfortunately, all efficient multiferroic composites have been reliant on stiff, brittle, and sometimes lead-based materials, which inhibits their implementation to wearable, biomedical, and soft robotic applications. Many prior soft and semi-organic multiferroic composites have been investigated and reported in literature, however they fall orders of magnitude short to their stiff and brittle counterparts. Thus, the objective of this project is to develop a novel class of soft semi-organic or completely organic multiferroic composites with considerable magnetoelectric coupling. The hypotheses of the proposed research is based on overcoming two engineering shortcomings of the prior semi-organic multiferroic research; namely the poor magnetostriction and property-mismatch arbitration. Therefore, two classes of composite materials are proposed which aim to replace the poorly performing ferromagnetic materials in prior studies with 1) giant magnetostrictive rare-earth alloy particulates or 2) newly discovered organic magnetic polymers. The composites were fabricated, analyzed, and characterized through computational and experimental techniques, including finite element analysis, explicit dynamic modeling, probe force microscopy, magnetometry, crystallography, dynamic mechanical analysis, dielectric analysis, terahertz and infrared spectroscopy, and other various testing methods. The culmination of the characterization techniques produces comprehensive property maps of these two composites which elucidates pitfalls and enlighten scientific foundations of how each material can beneficially or detrimentally affect the other. Results show the feasibility of these composites to fill various applications and illuminates a path for future studies to take soft multi

Organic semiconductors (OSCs), including semiconducting small molecules (SSMs), polymers (SPs) and carbon nanotubes (s-CNTs), are a versatile class of materials. Their compatibility with low-cost solution processing techniques and potential for producing lightweight, flexible, electronic devices has already begun to revolutionize several technologies. Typical organic devices, including thermoelectrics (OTEs), photovoltaics (OPVs), field-effect transistors (OFETs), and light-emitting diodes (OLEDs) can be fabricated with flexible OSCs, and has spawned several novel applications including wearable electronics, foldable low-temperature thermoelectrics, and flexible displays. While the future of OSC technology is promising, several structure-property relationships remain poorly understood, likewise the link between molecular doping level and OSC carrier density is underdeveloped. In my dissertation, I demonstrate new solution processing techniques, connect processing methods to structure formation using X-ray and neutron scattering probes, and correlate processing and structure formation to vital optoelectronic properties. I begin by demonstrating an additive solution process for depositing multiple layers of mutually soluble SP films without disrupting layer continuity. I use neutron reflectometry to quantify film thickness changes during processing steps and demonstrate the fabrication of a 4-layered device. Next, I perform a hierarchal structural analysis of bulk heterojunction SSM OPVs using grazing incidence X-ray diffraction and small angle neutron scattering, and correlate peak OPV performance to an inflection in film crystallinity and phase purity. Third, I refined a doping process, termed anion exchange doping, and show its effectiveness for doping high ionization energy polymers. During which I developed the framework for quantifying and predicting doping levels and carrier densities in SPs. Finally, I reveal record carrier mobilities and OTE performance in s

Redox flow batteries (RFBs) have demonstrated great potentials to store the renewable energies, coping with the problem of electricity generation-demand discrepancies. However, further development of the traditional metal based RFBs have been hindered by various techno-economic challenges, such as expensive redox active materials, low solubility, slow reaction kinetics, hazardous and corrosive electrolyte. On the other hand, organic RFBs technology has shown great ability of overcoming these challenges and be a good alternative to traditional inorganic based RFBs. Organic molecules are synthetically tuneable, allowing design of molecules with a combination of all the required properties of suitable redox active materials. This PhD work focuses on advancing and developing a competitive RFB technology through design, synthesis, and modification of organic materials. The designs involve mimicking all vanadium RFB chemistry to engineer bipolar organic molecules for applications in symmetric RFBs. This strategy helps mitigate crossover/cross contamination issues which causes capacity loss in RFBs based on different active materials as positive and negative electrolyte. First, an aqueous RFB that employs indigo carmine/2,2,6,6-Tetramethylpiperidinyl-N-oxyl (TEMPO) combined molecule as a bifunctional electroactive material is designed, synthesized and investigated. Cyclic voltammetry (CV) studies of the combined molecule indicate a reversible redox reaction of the leucoindigo carmine/indigo carmine redox couple at -0.62 V and the TEMPO (nitroxide radical/oxoammonium cation) redox couple at 0.52 V versus Hg/Hg2SO4, leading to a theoretical cell voltage of 1.14 V. The combined molecule demonstrated better electrochemical properties in comparison to the individual separate molecules as investigated by CV and rotating disc electrode experiments. A pumped cell test displays a charge/discharge cycle performance of over 70 consecutive cycles with nearly 100%

Highly controlled drug delivery devices play an increasingly important role in the development of new neuroengineering tools. Stringent - and sometimes contradicting - demands are placed on such devices, ranging from robustness in freestanding devices, to overall device miniaturization, while maintaining precise spatiotemporal control of delivery with high chemical specificity and high on/off ratio. Here, design principles of a hybrid microfluidic iontronic probe that uses flow for long-range pressure-driven transport in combination with an iontronic tip that provides electronically fine-tuned pressure-free delivery are explored. Employing a computational model, the effects of decoupling the drug reservoir by exchanging a large passive reservoir with a smaller microfluidic system are reported. The transition at the microfluidic-iontronic interface is found to require an expanded ion exchange membrane inlet in combination with a constant fluidic flow, to allow a broad range of device operation, including low source concentrations and high delivery currents. Complementary to these findings, the free-standing hybrid probe monitored in real time by an external sensor is demonstrated. From these computational and experimental results, key design principles for iontronic devices are outlined that seek to use the efficient transport enabled by microfluidics, and further, key observations of hybrid microfluidic iontronic probes are explained., Additional Funding agencies: FLAG‐ERA. Grant Number: JTC2017; EPIGRAPH. Grant Number: ANR‐17‐GRF2‐0001; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linköping University. Grant Number: 2009‐00971; A*MIDEX ION. Grant Number: 2IONXXID/REID/ID17HRU208

Organic solar cells incorporating non-fullerene acceptors (NFAs) have reached remarkable power conversion efficiencies of over 18%. Unlike fullerene derivatives, NFAs tend to crystallize from solutions, resulting in bulk heterojunctions that include a crystalline acceptor phase. This must be considered in any morphology-function models. Here, it is confirmed that high-performing solution-processed indacenodithienothiophene-based NFAs, i.e., ITIC and its derivatives ITIC-M, ITIC-2F, and ITIC-Th, exhibit at least two crystalline forms. In addition to highly ordered polymorphs that form at high temperatures, NFAs arrange into a low-temperature metastable phase that is readily promoted via solution processing and leads to the highest device efficiencies. Intriguingly, the low-temperature forms seem to feature a continuous network that favors charge transport despite of a poorly order along the pi-pi stacking direction. As the optical absorption of the structurally more disordered low-temperature phase can surpass that of the more ordered polymorphs while displaying comparable-or even higher-charge transport properties, it is argued that such a packing structure is an important feature for reaching highest device efficiencies, thus, providing guidelines for future materials design and crystal engineering activities.

Interface dipoles formed at an electrolyte/electrode interface have been widely studied and interpreted using the "double dipole step" model, where the dipole vector is determined by the size and/or range of motion of the charged ions. Some electron transport materials (ETMs) with lone pairs of electrons on heteroatoms exhibit a similar interfacial behavior. However, the origin of the dipoles in such materials has not yet been explored in great depth. Herein, we systematically investigate the influence of the lone pair of electrons on the interface dipole through three pyridine derivatives B2-B4PyMPM. Experiments show that different positions of nitrogen atoms in the three materials give rise to different hydrogen bonds and molecular orientations, thereby affecting the areal density and direction of the lone pair of electrons. The interface dipoles of the three materials predicted by the "double dipole step" model are in good agreement with the ultraviolet photoelectron spectroscopy results both in spin-coated and vacuum-deposited films. These findings help to better understand the ETMs/electrode interfacial behaviors and provide new guidelines for the molecular design of the interlayer., Funding agencies: The Swedish Research Council (project grants no. 2016-05498, 2016-05990, and 2020-04538), The Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO Mat LiU no. 2009 00971), The Open Fund of the State Key Laboratory of Luminescent Materials and Devices (South China University of Technology)

In times where research focuses on the use of organic polymers as a base for complex organic electronic applications and improving device efficiencies, degradation is still less intensively addressed in fundamental studies. Hence, advanced neutron scattering methods are applied to investigate a model system for organic electronics composed of the widely used conductive polymer blend poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) together with nanocellulose as flexible reinforcing template material. In particular, the impact of relative humidity (RH) on the nanostructure evolution is studied in detail. The implications are discussed from a device performance point of view and the changing nanostructure is correlated with macroscale physical properties such as conductivity. The first humidification (95% RH) leads to an irreversible decrease of conductivity. After the first humidification cycle, however, the conductivity can be reversibly regained when returning to low humidity values (5% RH), which is important for device manufacturing. This finding can directly contribute to an improved usability of emerging organic electronics in daily live., QC 20220228

Interface dipoles formed at an electrolyte/electrode interface have been widely studied and interpreted using the "double dipole step" model, where the dipole vector is determined by the size and/or range of motion of the charged ions. Some electron transport materials (ETMs) with lone pairs of electrons on heteroatoms exhibit a similar interfacial behavior. However, the origin of the dipoles in such materials has not yet been explored in great depth. Herein, we systematically investigate the influence of the lone pair of electrons on the interface dipole through three pyridine derivatives B2-B4PyMPM. Experiments show that different positions of nitrogen atoms in the three materials give rise to different hydrogen bonds and molecular orientations, thereby affecting the areal density and direction of the lone pair of electrons. The interface dipoles of the three materials predicted by the "double dipole step" model are in good agreement with the ultraviolet photoelectron spectroscopy results both in spin-coated and vacuum-deposited films. These findings help to better understand the ETMs/electrode interfacial behaviors and provide new guidelines for the molecular design of the interlayer., Funding agencies: The Swedish Research Council (project grants no. 2016-05498, 2016-05990, and 2020-04538), The Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO Mat LiU no. 2009 00971), The Open Fund of the State Key Laboratory of Luminescent Materials and Devices (South China University of Technology)